Background Tripartite Motif Containing 5 alpha (TRIM5α), a restriction factor produced ubiquitously in cells and tissues of the body plays an important role in the immune response against HIV. TRIM5α targets the HIV capsid for proteosomal destruction. Cyclophilin A, an intracellular protein has also been reported to influence HIV infectivity in a cell-specific manner. Accordingly, variations in TRIM5α and Cyclophilin A genes have been documented to influence HIV-1 disease progression. However, these variations have not been documented among Elite controllers in Uganda and whether they play a role in viral suppression remains largely undocumented. Our study focused on identifying the variations in TRIM5α and Cyclophilin A genes among HIV-1 Elite controllers and non-controllers in Uganda.
Methods PBMCs previously collected from HIV-1 Elite controllers and non-controllers were thawed, CD4+ T cells isolated and then cultured in presence of Anti-CD3 & Anti-CD28 for 48 hours in a CO2 incubator. RNA was extracted and RT qPCR was done using QuantiTect Probe RT-PCR Kit in a Rotor gene Q real-time PCR machine. mRNA was quantified using the delta CT relative quantification method. DNA was extracted using Qiagen Blood Genomic DNA Kit, PCR amplified and sequenced the exon 2 of TRIM5α and the promoter region of the CyclophillinA gene. Sequence data were analyzed using Mutation Surveyor to identify Single Nucleotide Polymorphisms (SNPs).
Results From the sequence analysis, the rs10838525 G>A mutation in exon 2 of TRIM5α was found only among elite controllers (30%) while the rs3824949 was seen among 25% of the non-controllers. In the Cyclophilin A promoter, rs6850 was seen among 62.5% of the non-controllers and only among 10% elite controllers. rs17860048 was predominantly seen among elite controllers (30%) and 12.5% non-controllers. From gene expression analysis, we noted that the respective genes were generally elevated among elite controllers, however, this difference was not statistically significant (TRIM5α p=0.6095; Cyclophilin A p=0.6389).
Conclusion Variations in TRIM5α and Cyclophillin A promoter may influence HIV viral suppression. The rs10838525 SNP in TRIM5α may contribute to viral suppression among HIV-1 elite controllers. The rs6850 in the cyclophillin A gene may be responsible for HIV-1 rapid progression among HIV-1 non-controllers.